Posts Tagged ‘hazard analysis’

Ever overdraw on your checking account or max out a credit card? It’s not hard to do if you’re not keeping track of things. How can we manage household expenses without some sort of record keeping?

Away from home, in the business sector, record keeping becomes even more important. In fact, it’s the very thing covered by HACCP Design Principle No. 7.

Principle 7: Establish record keeping procedures. – This HACCP principle requires that all food manufacturing plants maintain records to show they implemented a HACCP plan, are following all principles, and the plan is working effectively.

Let’s look at an example. In keeping with the directive of HACCP Design Principle 7, the engineering department of a food manufacturing plant must keep records for each design project. The design record for a new cookie forming machine would contain things like engineering calculations to determine strength requirements of machine parts and supports, as well as power requirements for the electric motor that drives the machine. This design record would also contain documentation concerning materials selected to construct the machine, as well as dimensioned mechanical drawings of the machine and its parts. These dimensioned drawings will show all physical dimensions of the machine and its constituent parts.

The record would also contain test results and analysis of the results. Lastly, the design record must include a risk analysis of potential hazards that could result. Other activities include identification of CCPs, establishment of critical limits, and other factors in accordance with HACCP Design Principles 1 through 5. In other words, the record must be complete, bearing witness to an effective adherence to HACCP Design Principles 1 through 5.

Principle 7 also encompasses guidelines set in place through Design Principle 6, which calls for the establishment of procedures to govern Principles 1 through 5. A complete record would contain the procedures themselves, along with any revisions. It would also contain documentation that the procedures were reviewed and approved by management along the way.

Finally, of what use would records be if they were incomplete, disorganized, and outdated? A document control system not only establishes procedures, but assigns responsibilities to personnel within the department for filing design records to make sure that everything is up to snuff. This system would encompass everything, from the creation of engineering documents, to their timely entry into the record keeping system.

We have now exhausted our discussion on HACCP Design Principles. We’ll switch to a new topic next time, examining some basic concepts behind the control of industrial equipment and machinery.

Imagine a doctor not washing his hands in between baby deliveries. Unbelievable but true, this was a widespread practice up until last century when infections, followed by death of newborns, was an all-too common occurrence in hospitals across the United States. It took an observant nurse to put two and two together after watching many physicians go from delivery room to delivery room, mother to mother, without washing their hands. Once hand washing in between deliveries was made mandatory, the incidence of infection and death in newborns plummeted.

Why wasn’t this simple and common sense solution instituted earlier? Was it ignorance, negligence, laziness, or a combination thereof that kept doctors from washing up? Whatever the root cause of this ridiculous oversight, it remains a fact of history. Common sense was finally employed, and babies’ lives saved.

The same common sense is at play in the development of the FDA’s Hazard Analysis Critical Control Point (HACCP) policy, which was developed to ensure the safe production of commercial food products. Like the observant nurse who played watchdog to doctors’ poor hygiene practices and became the catalyst for improved hospital procedures set in place and remaining until today, HACCP policy results in a proactive strategy where hazards are identified, assessed, and then control measures developed to prevent, reduce, and eliminate potential hazards.

In this article, we’ll begin to explore how engineers design food processing equipment and production lines in accordance with the seven HACCP principles. You will note that here, once again, the execution of common sense can solve many problems.

Principle 1: Conduct a hazard analysis. – Those involved in designing food processing equipment and production lines must proactively analyze designs to identify potential food safety hazards. If the hazard analysis reveals contaminants are likely to find their way into food products, then preventive measures are put in place in the form of design revisions.

For example, suppose a food processing machine is designed and hazard analysis reveals that food can accumulate in areas where cleaning is difficult or impossible. This accumulation will rot with time, and the bacteria-laden glop can fall onto uncontaminated food passing through production lines.

As another example, a piece of metal tooling may have been designed with the intent to form food products into a certain shape, but hazard analysis reveals that the tooling is too fragile and cannot withstand the repeated forces imposed on it by the mass production process. There is a strong likelihood that small metal parts can break off and enter the food on the line.

Next time we’ll move on to HACCP Principle 2 and see how design engineers control problems identified during the hazard analysis performed pursuant to Principle 1.

Try this for a tongue-twister: Coal fired electric utility power plant boiler… If you’ve been reading along with us for the last couple of weeks, you now have a pretty good idea of what these are and what they do.

These boilers are contained within furnaces in coal fired power plants. The furnace’s job is to combine coal and air to create a combustion process. It is like a big, insulated enclosure that keeps the heat energy from the combustion process from escaping before it can be absorbed by the water and steam in the boiler tubes. The heat energy is then funneled to the steam turbine to spin an electrical generator, creating the energy which will eventually find its way into our homes and businesses.

During the operation of the boiler, coal and air must be introduced into the furnace at carefully measured rates to maintain a proper fuel-to-air ratio which will enable the release of heat energy from the coal at a safe, controlled rate. Fuel-air ratio is the amount of coal entering the furnace divided by the amount of air entering the furnace. If this ratio isn’t precisely maintained, conditions may be right for an explosion to occur. Specifically, the ratio has to fall within an “explosive range.” Once within this range, all that is needed is an ignition source, such as hot ash, or even mere static electricity, and the result may be a furnace explosion.

There are certain times at which furnace explosions are more likely to occur than others, such as when the boiler is being started, operated at less than full capacity, or shut down. When a furnace explodes, a pressure wave moves out from the center of the blast. This pressure wave will bear up against the sides of the furnace with great force, and if the pressure is high enough the sides of the furnace, which are made of heavy steel components, will actually bend and split open. Boiler tubes may even rupture, releasing high pressure steam and water into the power plant and furnace. At the very least, the boiler will be down for expensive repairs and no electricity can be produced by its turbine generator. This down time can last for many months and results in lost revenue to the energy producer.

Aside from an explosive fuel-to-air ratio, there are other potential causes of furnace explosions. For example, poor coal quality can lead to incomplete combustion, or the flame going out completely, encouraging unburned coal particles to settle and accumulate in the furnace. The accumulation of coal can grow to the point where it forms an explosive mixture when combined with the right amount of air.

So how can boiler explosions be prevented? The National Fire Protection Association (NFPA) looked into the problem and developed an industry standard. This standard is known as NFPA 85, Boiler and Combustion Systems Hazards Code. Its purpose is to contribute to operating safety and prevent uncontrolled fires, explosions, and implosions of coal fired boilers. NFPA 85 lays out guidelines to follow when designing, building, and operating boiler fuel handling systems, air handling systems, and combustion control systems. Following its guidelines will certainly significantly decrease the probability of explosions occurring.

Another means of explosion prevention includes implementing a boiler operator training program. These enable attendees to better understand operating procedures and equip them with the knowledge to safely control the combustion process, particularly when a furnace explosion is most likely to occur. This training can be done with a combination of classroom instruction along with time on a simulator and may be followed up with hands-on training in the plant itself.

Lastly, boiler explosions can be prevented by implementing an effective inspection and maintenance program to locate and repair or replace boiler components, averting the possibility of a potential disaster occurring. Things such as check lists can be used to ensure that nothing is missed. This is a strategy that all pilots must use before starting their planes, and it is now being used in hospitals as well to cut back on the rate of patient infection due to carelessness on the part of hospital staff.

Hey, we’re all human, and humans are not perfect. But remember that an ounce of prevention is truly worth a pound of cure, and then some. A properly placed check on the list could mean lives will be saved.